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Bosch Rexroth ctrlX OS (Pro)

Overview

Section titled “Overview”

The ctrlX Interface connects realvirtual directly to any ctrlX OS device like the Bosch Rexroth ctrlX CORE controller. It uses the realvirtual WebSocket Bridge — a .NET 8 snap application running on ctrlX OS — to exchange PLC signals in real time via the ctrlX Data Layer.

Communication uses the high-performance WebSocket Realtime Interface v2 protocol, enabling cyclic signal exchange at millisecond intervals. The ctrlX Interface extends the WebSocket Realtime Interface with ctrlX OS-specific features: REST API authentication, device status monitoring, remote bridge configuration, ctrlX Data Layer settings, and diagnostics — all from the Unity Inspector.

Key capabilities:

  • High-speed signal exchange via WebSocket with configurable publish intervals down to 5 ms
  • One-click signal import from ctrlX Data Layer with automatic signal discovery
  • REST API integration for device info, bridge status, and diagnostics
  • Remote bridge configuration (publish interval, browse paths, logging level)
  • Data Layer settings (min publish/sample intervals)
  • SSL/TLS support for secure connections through the ctrlX reverse proxy

Architecture

Section titled “Architecture”
 Unity (realvirtual)                      ctrlX OS device
┌─────────────────────┐          ┌──────────────────────────────┐
│                     │          │                              │
│   ctrlX Interface ──┼── WebSocket v2 ──▶ WebSocket Bridge    │
│                     │          │               │              │
│                  ───┼── REST API ─────▶ ctrlX Data Layer     │
│                     │          │               │              │
│                     │          │          PLC Runtime         │
│                     │          │                              │
└─────────────────────┘          └──────────────────────────────┘

The ctrlX Interface communicates with ctrlX OS devices through two channels:

  • WebSocket v2 — High-speed cyclic signal exchange using the WebSocket Realtime Interface v2 protocol. See that page for the full wire format specification.
  • REST API — Authentication, device info, bridge configuration, Data Layer settings, and diagnostics.

realvirtual WebSocket Bridge

Section titled “realvirtual WebSocket Bridge”

The realvirtual WebSocket Bridge is a .NET 8 snap application that runs on ctrlX OS. It bridges the ctrlX Data Layer to realvirtual Unity Digital Twins via the WebSocket Realtime Interface v2 protocol.

realvirtual WebSocket Bridge installed on a ctrlX OS device

The bridge includes a built-in status page accessible via the ctrlX OS web interface, showing connection status, signal counts, write activity monitoring, and browse path configuration at a glance.

realvirtual WebSocket Bridge status page showing connection status, signal counts, and write activity monitoring

The bridge:

  • Subscribes to ctrlX Data Layer nodes and publishes their values over WebSocket
  • Receives signal updates from Unity and writes them back to the Data Layer
  • Supports configurable browse paths, publish intervals, and logging levels
  • Can be configured remotely from the Unity Inspector

Setup

Section titled “Setup”

Prerequisites

Section titled “Prerequisites”
  1. A ctrlX OS device like ctrlX CORE (physical or virtual)
  2. The realvirtual WebSocket Bridge snap installed on the ctrlX OS device (available from realvirtual on demand)
  3. Network connectivity between your PC and the ctrlX OS device

Adding the Interface

Section titled “Adding the Interface”
  1. In Unity, go to the menu Tools > realvirtual > Interfaces > ctrlX Interface to add the component
  2. Enter the ctrlX Address (IP address of your ctrlX OS device)
  3. Set Username and Password (default: boschrexroth / boschrexroth)
  4. Click Refresh to verify the connection and see device info

ctrlX Interface Inspector

Importing Signals

Section titled “Importing Signals”
  1. Make sure the ctrlX OS device is reachable and the bridge snap is running
  2. Configure Browse Paths to point to your PLC symbols (e.g. plc/app/Application/sym)
  3. Click Import Signals in the Connection section
  4. The interface connects to the bridge, discovers all signals, and creates local PLC signal objects as children

Quick Start

Section titled “Quick Start”
  1. Add the ctrlX Interface to your scene
  2. Enter ctrlX address and credentials
  3. Click Refresh to verify connectivity
  4. Configure browse paths for your PLC program
  5. Click Import Signals to create signal objects
  6. Press Play — signals exchange automatically

Properties

Section titled “Properties”

Connection

Section titled “Connection”
PropertyDescription
ctrlX AddressIP address of the ctrlX OS device (e.g. 192.168.1.1)
UsernameLogin username for ctrlX REST API (default: boschrexroth)
PasswordLogin password for ctrlX REST API (default: boschrexroth)
Use SSLEnable for wss:// connections through the ctrlX reverse proxy. When enabled, port switches to 443 and path is set automatically

Status

Section titled “Status”
PropertyDescription
ctrlXDevice info: operating mode, hostname, OS version, architecture
BridgeInstalled bridge snap version and status
WebSocketCurrent WebSocket connection state (Connected / Disconnected)
SignalsNumber of input and output signals
Comm CycleActual communication cycle time in milliseconds
ConfigLast configuration operation result

Buttons:

  • Refresh — Fetches device info and bridge status from ctrlX via REST API
  • Test ctrlX — Tests REST connectivity by authenticating and reporting the result
  • Test Bridge — Tests WebSocket connectivity to the bridge application

Signal Import Configuration

Section titled “Signal Import Configuration”
PropertyDescription
Default DirectionDirection for imported signals when no pattern matches (Input or Output)
Use Pattern MatchingEnable name-based direction detection using the patterns below
Input PatternsName substrings that identify signals Unity writes to the PLC (e.g. "Unity")
Output PatternsName substrings that identify signals the PLC writes to Unity

Bridge Configuration

Section titled “Bridge Configuration”
PropertyDescription
Publish Interval (ms)How often the bridge publishes signal updates over WebSocket (default: 5 ms)
Logging LevelBridge log verbosity: Debug, Information, Warning, or Error
Browse PathsData Layer path prefixes for signal auto-discovery (e.g. plc/app/Application/sym)
RecursiveBrowse sub-folders recursively when discovering signals

Changes to bridge configuration are tracked and auto-applied after a short delay.

Data Layer Settings

Section titled “Data Layer Settings”
PropertyDescription
Min Publish Interval (ms)ctrlX Data Layer global minimum publish interval in milliseconds (default: 10)
Min Sample Interval (µs)ctrlX Data Layer global minimum sample interval in microseconds (default: 10000)

Buttons:

  • Get DL — Reads current Data Layer subscription settings from ctrlX
  • Apply DL — Writes the configured values to ctrlX Data Layer settings

Bridge Logs

Section titled “Bridge Logs”
PropertyDescription
Log CountNumber of log entries to fetch from ctrlX diagnostics
Bridge Logs OnlyFilter to show only bridge snap log entries
Forward to ConsoleWrite each fetched log entry to the Unity console

Buttons:

  • Fetch Logs — Retrieves recent log entries from ctrlX OS diagnostics
  • List Packages — Lists all installed snaps on the ctrlX OS device

Advanced

Section titled “Advanced”
PropertyDescription
WebSocket PortTCP port for WebSocket communication (default: 8080, auto-set to 443 when SSL is enabled)
Update Cycle (ms)Communication thread update interval in milliseconds
Client NameIdentification name sent during WebSocket handshake
Connect On PlayAutomatically connect when entering play mode
Only Transmit ChangedOnly send signals whose values changed since the last cycle
Auto ReconnectAutomatically reconnect on connection loss
Debug ModeEnable detailed logging for troubleshooting

SSL / Reverse Proxy

Section titled “SSL / Reverse Proxy”

When Use SSL is enabled:

  • The port is automatically set to 443
  • The WebSocket path is set to /ctrlx-rv-bridge/ws for routing through the ctrlX reverse proxy
  • All REST API calls use HTTPS
  • Self-signed certificates are accepted (common for ctrlX devices on local networks)

When SSL is disabled, the interface connects directly to the bridge on port 8080 without encryption.

Troubleshooting

Section titled “Troubleshooting”

“Refresh” shows no device info:

  • Verify the ctrlX address is correct and the device is reachable (ping)
  • Check username and password — default is boschrexroth / boschrexroth
  • Use Test ctrlX to verify REST API connectivity

Bridge shows “not found”:

  • Install the realvirtual WebSocket Bridge snap on the ctrlX device
  • Check that the snap is in active state

WebSocket stays “Disconnected” during play:

  • Verify the bridge snap is running on the ctrlX OS device
  • Check WebSocket Port matches the bridge configuration (default: 8080)
  • If using SSL, ensure port 443 is accessible and the bridge is behind the ctrlX reverse proxy
  • Enable Debug Mode for detailed connection logging

Signals not importing:

  • Check that Browse Paths point to valid Data Layer nodes (e.g. plc/app/Application/sym)
  • Enable Recursive to discover signals in sub-folders
  • Verify the PLC application is loaded and running on the ctrlX OS device

Wrong signal directions after import:

  • Configure Input Patterns and Output Patterns to match your naming convention
  • Or set the Default Direction to match the majority of your signals

See Also

Section titled “See Also”